Mechanism for selecting containers according to length



R. B. FITCH June 13, 1961 Filed Nov. 26, 1957 o o o o o o o o QN T g 83% S Q N\ ma lu INVENTOR.

ATTORNEYS.

United States Patent G i 2,988,214 MECHANISM FOR SELECTING CONTAINERS ACCORDING TO LENGTH Robert Fitch, Montville, N.J., assignor to Stapling Machines 00., Rockaway, N .J a corporation of Delaware Filed Nov. 26, 1957, Ser. No. 699,115 8 Claims. (Cl. 209-71) This invention relates to a mechanism for selecting from among boxes or cartons of difierent lengths those boxes which have a given or pre-selected length.

An object of this invention is to provide such a machine which is rugged and reliable but which at the same time is relatively simple and inexpensive.

Another object is to provide a mechanism of this kind which can be added to new or to existing installations to give a fully automatic box selection operation.

These and other objects will in part be understood from and in part pointed out in the description given hereinafter.

Various kinds of produce are packed in dilferent sizes of boxes according to industry standards and in the case of a packing house handling many different items, a variety of sizes of boxes must be dealt with. For greater operating convenience and to permit the handling of all boxes on the same conveyor equipment, it is desirable to have some way of automatically separating the boxes according to their lengths at the various operating stations. The present invention provides a simple and efiicient machine for performing this function.

In accordance with the present invention, there is provided in combination with any suitable conveyor section, such as one having small individual horizontally mounted rollers, a pair of treadles and a box barrier or railing con trolled by them. The treadles are positioned so that as boxes pass along the conveyor they selectively depress the treadles, this operation occurring in proper sequence to raise the barrier and stop a box only when a box of preselected length is passing. Boxes of other lengths, either longer or shorter, though they actuate the treadles, nonetheless are not stopped by the barrier. This mechanism is easily adjusted to select boxes of any length from short to long and its operation is very reliable. It can without undue expense be incorporated in existing in stallations, such as the machines shown in U.S. Patents 2,517,710; 2,550,292; and 2,565,987, for example.

A better understanding of the invention together with a fuller appreciation of its many advantages will best be gained from a study of the following description given in connection with the accompanying drawings, in which:

FIGURE 1 is a plan view of the central portion of a machine embodying features of the invention; and

FIGURE 2 is a side section view taken as indicated by lines 2-2 in FIGURE}.

V The machine 10 shown in FIGURES l and 2 includes a generally horizontal conveyor section, generally indicated at 12, adapted to carry boxes or crates, such as box 14 seen in FIGURE 2, from left to right. Conveyor section 12 includes two laterally spaced rows of rollers 16 each supported for rotation on a respective one of the horizontal stub shafts 18. These shafts in turn are supported from a portion of the stationary frame 20 of the machine.

Positioned centrally between the rows of rollers and on a level with them is the top run of an endless drive chain 22. The left and right ends of this chain are supported on the idler sprockets 24 and 26 respectively and the chain is driven by a sprocket and motor (not shown) engaging its bottom span. Each box moving onto the left end of conveyor section 12 from a supply conveyor (not shown) is with light friction engaged underneath by Patented June 13, 1961 chain 22 and carried to the right unless the movement of the box in this direction is positively prevented by the selecting mechanism provided in accordance with the invention.

Positioned near the forward or right end of conveyor section 12 is a barrier or stop member 30 which lies just below the level of the conveyor as indicated by solid lines, but which can be raised up, as indicated by the dotted lines, to block the passage of any given box.

Barrier 30 is mounted on a pair of parallel arms 32 and 34 which are pivotally mounted on the shaft 36. This shaft in turn is supported between a pair of links 38 extending downwardly roughly at right angles to arm 34. The lower end of links 38 is pivoted at 40 to frame 20. Also connected to pivot 40 is the tension spring 42 whose other end is fastened at '44 to the forward end of arm 34. The counterclockwise limit of links 38 is adjustable relative to frame 20 by means of the set screw 46 but these links can swing clockwise about pivot '40. The pull of spring 42 urges barrier 30 upward but this action can be defeated by the following elements.

Arm 32 closely adjacent barrier 30 carries a pin 50 which can be engaged from above by the hooked end of a rod 52 extending downward. The lower end of this rod is pivoted at 54 to the see-saw link 56 whose center is pivoted at 58 to frame 20. Similarly, the forward end of arm 34 carries a tab 60 which can be engaged from beneath by the upper end of a rod 62. The lower end of this rod is pivoted at 64 to another see-saw link 66 whose center is pivoted at 68, opposite pivot 58, to frame 20. When rod 52 is pulled down its upper end pulls down on pin 50 and draws barrier 30 down. to the position shown. Rod 52 is normally held in down position by link 56 which is biased at a point just to the left or be hind its pivot 58 by the tension spring 70, the force of this spring being sufiicient to pull barrier 30 down against the action of spring 42.

The rear-most end of link 56 is adjustably pivoted at 72 to a short link 74 whose upper end is pivoted at 76 to the forward treadle 78. The rear end of the treadle is pivoted at 80 to frame 20. When a box passes over the treadle it will be depressed from the position shown to the level of the conveyor thereby raising the forward end of see-saw link 56 and rod 52. This releases pin 50 and allows barrier 30 to rise, under the action of spring 42, assuming of course that rod 62 is down out of engagement with tab 60. This condition occurs at the proper instant necessary to raise the barrier and stop a box only when a box of preselected length is passing. All other boxes, though they may raise the barrier, will not be stopped by it as will appear.

The rear end of see-saw link 66 is adjustably pivoted at 82 to a short link 84 whose upper end is pivoted at 86 to the rear treadle 88. The rear end of the treadle is pivoted at 90 to frame 20. See-saw link and the elements connected to it are biased to the position shown by the tension spring 92 connected to the link just behind its center pivot 68. When treadle 88 is depressed to the level of the conveyor by a passing box, rod 62 will move up, engage tab 60, and prevent barrier 30* from lifting even though rod 52 may, in the meantime, have risen and released pin 50. The barrier is permitted to rise only if rear treadle 83 is not depressed but forward treadle 78 is depressed, provided also that a box is not then above the barrier. A box which satisfies these conditions will only be one whose length is greater than the distance from the barrier to front treadle 78 but less than the distance from the barrier to rear treadle 83. A box of greater length will not have released rear treadle 88 before it moves over barrier 30, while a box of lesser length will have released both treadles before it reaches the barrier.

To provide automatic stopping of the :motor driving chain 22 when a proper size box comes against barrier 30, the arms which carry the barrier have been made free to move with their pivot 36 a short distance forward, i.e. to the right, parallel to the conveyor. This movement in turn results in the opening of an electric switch in series with the motor. To this end, barrier 30 carries on its underside a downwardly projecting plate 94 which carries an adjustable stop screw 96. Positioned to the right opposite this screw is a pin 98 which when depressed opens the normally closed switch 100 mounted on frame 20. When a box bumps against the barrier, screw 96 depresses pin 98 and limits further forward travel of the barrier while the pin in turn opens switch 100 and stops the drive motor, the motor remaining off for so long as the box pushes against the barrier. When this box is removed,

treadle 78 will be released and barrier 30 will return to the position shown in solid lines thereby permitting switch 100 to close and the motor to start. In some instances, it may be desirable to have switch 1001initiate other operations, such as starting a box'closing machine-at this station when a box arrives and is stopped. It may also be desired not to use switch 100to stop the conveyor chain, but merely to initiate movement of members which operate upon the box while the chain continues to run.

The above description of the invention is intended in illustration and not in limitation. Various changes may occur to those skilled in the art and these may be made without departing from the spirit or scope of the invention as set forth.

I claim:

1. A mechanism for selecting containers according to length comprising means defining a generally horizontal conveyor and including a drive mechanism, stop means positioned normally clear of said conveyor but adapted to move athwart it, first and second box sensing members spaced apart along the direction of travel along said conveyor and placed ahead of said stop means, and means interconnecting said members with said stop means so that said means is actuated when the closer one of said members senses a box but is not actuated when both members sense a box at the same time, said members each comprising a treadle projecting above said conveyor and adapted to be depressed by a box, and wherein the distance between said stop means and the farther one of said treadles is greater than the length of a box to be selected and the distance between the closer treadle and said stop means is less than the length'of a box to be selected.

2. The machine as in claim 1 wherein said stop means comprises a barrier adapted to rise from below to above the level of said conveyor, said barrier being spring urged up but held down when both of said treadles are up and permitted to move up only when said closer treadle is depressed alone.

3. The structure as in claim 2 wherein said barrier is free to move parallel to said conveyor upon impact of a box and in further combination with switch means to stop said conveyor drive mechanism when a box strikes said barrier.

4. A machine for selecting boxes, crates and the like according to length, and having a generally horizontal conveyor, a stop member adapted to move into or out of the path of travel of boxes on the conveyor, a first treadle positioned ahead of said member and normally projecting into the path of travel but movable out of said path by a box in passing, spring means urging said member into said path, a linkage interconnecting said member and said treadle to move said member out of said path against the action of said spring means when said treadle is in said path but permitting said member to move into said path when said treadle is moved out of said path, a switch to stop said conveyor, and means carried by said stop member to open said switch when a box bumps against said stop member. 7 I

5. The structure as in claim 4 'whereinsa'idstop' member is carried on a pivoted horizontalarm in turn carried on a' short generally vertical'arrn pivotedat its lower end to a stationary point so that said stop member is free to be raised or lowered relative to said conveyor and also to move parallel to it.

6. The structure as in claim 5 wherein said linkage includes a see-saw link pivoted near its center to a stationary point and pivoted at its forward end to a vertical rod,

said rod being adapted to pull said stop member down out of the-path of the containers on said conveyor, said see-saw link being connected at its rear end by a short link to said treadle, said see-saw link being spring biased with its forward end down.

7. The structure as in claim 6 in further combination with a second treadle and a see-saw linkage interconnected to said stop member, the forward end of said second linkage being spring biased down, and a push rod pivoted to the forward end of said second linkage and adapted to move upward and move said stop member down, said second treadle being positioned ahead of said first treadle and slightly farther from said stop member.

8. In a mechanism for selecting containers and boxes according to length, a stationary frame, means defining a generally horizontal conveyor and including an endless drive chain adapted to be driven by a motor to convey containers from left to right on said conveyor, a barrier positioned transversely of the path of travel of said containers along said conveyor and adapted to move up into or down out of said path near its right end, a horizontal arm pivoted near its mid-point on a shaft which is free to move a limited amount parallel to and beneath said conveyor, the left end of said arm carrying said barrier, a first box sensing member positioned near the left end of said run and adapted to project upward but to be depressed by a box in passing, a second box sensing member like the first but positioned to the right of the first and closer to said barrier, a first linkage interconnecting said first member with the right end of said horizontal arm so that when said first member is depressed said barrier is held down and when said first member is free said barrier is permitted by said first linkage to move upward, a second linkage interconnecting said second member with the left end of said horizontal arm so that when said second member is depressed said barrier is permitted by said second linkage to move up but when said second member is free said barrier is held down, and a switch actuated by a container striking said barrier to stop said motor.

References Cited in the'file of this patent UNITED STATES PATENTS 

